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New multicomponent reactions involving an isocyanide, terminal or internal alkynes, and endohedral metallofullerene (EMF) Lu3 N@C80 yield metallofulleroids which are characterized by mass-spectrometry, HPLC, and multiple 1D and 2D NMR techniques. Single crystal studies revealed one ketenimine metallofulleroid has ordered Lu3 N cluster which is unusual for EMF monoadducts. Computational analysis, based on crystallographic data, confirm that the endohedral cluster motion is controlled by the position of the exohedral organic appendants. Our findings provide a new functionalization reaction for EMFs, and a potential facile approach to freeze the endohedral cluster motion at relatively high temperatures.

The electrocatalytic properties of some endohedral fullerenes for hydrogen evolution reactions (HER) were recently predicted by DFT calculations. Nonetheless, the experimental catalytic performance under realistic electrochemical environments of these 0D-nanomaterials have not been explored. Here, for the first time, we disclose the HER electrocatalytic behavior of seven M3N@2n (2n = 68, 78, and 80) fullerenes (Gd3N@Ih(7)-C80, Y3N@Ih(7)-C80, Lu3N@Ih(7)-C80, Sc3N@Ih(7)-C80, Sc3N@D5h(6)-C80, Sc3N@D3h(5)-C78, and Sc3N@D3(6140)-C68) using a combination of experimental and theoretical techniques. The non-IPR Sc3N@D3(6140)-C68 compound exhibited the best catalytic performance toward the generation of molecular hydrogen, exhibiting an onset potential of -38 mV vs RHE, a very high mass activity of 1.75 A·mg-1 at -0.4 V vs RHE, and an excellent electrochemical stability, retaining 96% of the initial current after 24 h. The superior performance was explained on the basis of the fused pentagon rings, which represent a new and promising HER catalytic motif.

In this work, two new C70 isomers, α and β bis(2-(thiophen-2-yl)ethyl)-C70-fullerene mono-adducts (DTC70), were synthesized, characterized and used as electron transporting materials (ETMs) in perovskite solar cells (PSCs). Our results show that the α isomer improves both the Jsc and FF values of the devices, when compared to the results for the β-isomer and to those for phenyl-C70-butyric acid methyl ester (PC71BM), used as control. Devices based on α-DTC70 achieved a power conversion efficiency (PCE) of 15.9%, which is higher than that observed with PC71BM (15.1%).

The functionalization of endohedral metallofullerenes by halogenation has not been previously reported and remains a challenging endeavor in carbon nanoscience. In this work, we show that halogenation of endohedral metallofullerenes is predicted to be feasible based on thermodynamic grounds by means of DFT computations, combined with in situ experimental investigations. Computed bond energies for the chlorination, fluorination and hydrogenation of endohedral metallofullerenes that span a range of cage sizes are found to be comparable to those of known halogenated and hydrogenated empty fullerenes. Therefore, we propose that new forms of functionalized metallofullerenes should be synthesized under appropriate experimental conditions, despite many prior unsuccessful attempts. Indeed, we experimentally show for the first time that M@C2n (M = metal) metallofullerenes and the prototypical Sc3N@C80 clusterfullerene can be fluorinated by two different routes under the typical ‘harsh’ gas phase conditions of metallofullerene plasma synthesis, and at lower extents that could avoid cage degradation. The combination of halogenation and metal encapsulation offers the potential to create new radical-quenched, functionalized endohedral metallofullerenes that possess stable, large-gap carbon cages. These results open new avenues for the synthesis and stabilization of encapsulated molecular nanocarbons.